Fuels used in today's automotive engine cause deposits to be formed during combustion. Such deposits collect on parts of the combustion chamber including valves, spark plugs, and cylinder heads and walls. Formation of these deposits can result in increased exhaust emissions.
Cyclopentadienyl manganese compounds are excellent antiknocks in gasolines used to operate internal combustion engines and have proven to be especially beneficial in solving some of the problems present when low-lead or lead-free gasolines are used with internal combustion engines.
Use of such compounds as antiknocks is described in U.S. Pat. Nos. 2,818,417, 2,839,552, and 3,127,351, all incorporated herein by reference.